This isn't true. He had both a "nowcast" (if the election were held today) and a prediction of the final result. The only change in that regard between 2016 and now was to stop publishing the nowcast.

Edit: Even after your edit I don't think the claim is true. The probabilities in this election didn't change much because the campaign season was comparatively uneventful and the polling didn't change much, not because of a fundamental change in the model. 2016 had tons of bombshell events which is what caused the chaos in the prediction model.